| Named By: | Marta Fernandez in 1977 |
| Time Period: | Late Jurassic - Early Cretaceous, Tithonian-Berriasian |
| Location: | Argentina |
| Size: | Unavailable |
| Diet: | Piscivore/Carnivore |
| Fossil(s): | Partial remains |
| Classification: | | Chordata | Reptilia | Ichthyosauria | Ophthalmosauridae | Platypterygiinae | |
Caypullisaurus is an extinct genus of large platypterygiine ophthalmosaurid ichthyosaur from the Late Jurassic to the Early Cretaceous (Tithonian and Berriasian stages) of Argentina. Its holotype was collected from the Vaca Muerta formation of Cerro Lotena, Neuquen, dating to the early Tithonian stage of the Late Jurassic, about 150 million years ago. Caypullisaurus was first named by Marta Fernandez in 1997 and the type species is Caypullisaurus bonapartei. It is a member of the family Ophthalmosauridae, and closely related to Platypterygius and Brachypterygius. In 2012, Caypullisaurus was found to be most closely related to Athabascasaurus and "Platypterygius" australis, and to nest within the subfamily Platypterygiinae.